Stapes pathology in otosclerosis: scanning electron microscopic examination.

The human stapes is still a subject of considerable interest both to the clinician and to the research investigator. This is due to the stapes position between the middle and inner ear, and because of its involvement in the otosclerotic process. The purpose of this study was to determine scanning electron microscopic and histopathological features of normal and otosclerotic stapes. The specimens were obtained from adult human temporal bones and during operation of patients with otosclerosis. Our results show that the surface of the normal stapes had various degrees of structural features. The otosclerotic stapes is characterized by a typical irregular pattern. Histological examination of the stapedial footplate or its fragments showed three types of otosclerotic lesions: fibrotic, sclerotic, and spongiotic. Our observations could support the hypothesis that otosclerosis is not a static disease.